LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
the range of materials tested (including many materials not representative of commercial LAS) and
the differences in test design (not necessarily following standard guidelines). Consequently, the
range of LC50 values for fish presented by Van d Plassche et al. was only provided for one species
(Pimephales promelas, 0.40-100 mg/L) as an example of the wide ranges found. These values
include mixtures of chemicals in addition to commercial LAS products. It is unclear which values
within the range refer to the commercial LAS products and the individual records were not
available for validation.
Van de Plassche et al. (1999) did calculate the geometric mean values for seven species of fish, as
shown in Table 9 below, and found the interspecies variation decreases considerably when the
geometric mean value per species is calculated. This comparison indicates that the large variation
found (e.g., P. promelas LC50 values ranged from 0.4-100 mg/L; geometric mean = 3.2 mg/L) is
due primarily to the wide range of materials tested and differences in test designs.
Species
Table 9. Geometric Mean Fish LC50 Toxicity Results 1
Lepomis macrochirus (bluegill sunfish, dossier
section 4.1c)
Pimephales promelas (fathead minnow,
dossier section 4.1d)
Leusiscus idus melanotus (golden orfe, dossier
section 4.1e)
Carassius auratus (goldfish, dossier section
4.1f)
Oncorhynchus mykiss (rainbow trout, dossier
section 4.1f)
Geometric Mean (Range)
LC50 (mg/L)
3.0 88
3.2
(0.4-100 mg/L)
Number of Records
UNEP PUBLICATIONS 37
35
2.9 11
9.5 46
3.0 10
Oryzias latipes (medaka, dossier section 4.1f) 13 5
Poecilia reticulata (guppy, dossier section 4.1f) 3.8 9
1 Reliability of Studies = (4); Original Data Not Reviewed
HERA (2004) conducted an extensive search of the data previously compiled by BKH (1993) and
the published and unpublished literature since this data compilation for studies on commercial LAS
and on species for which standardized test methodologies are available. As described in Appendix
2, a total of 18 fish studies were identified. Of these 11 studies were found to have been conducted
using currently relevant LAS (C11.6-C11.8) and valid test methods. LC50 values ranged from 1.67-7.7
mg/L with no values below 1 mg/L. A robust summary for the study representing the lowest value
for fish (critical study) was prepared and the study reference is provided in Table 10.